Method for the correction of malfunctioning muscles of mastication



April 8, 1958 J H, sHAcKELFoRD 2,829,639

METHOD FOR THE CORRECTION OF MALFUNOTIONING MUSCLES OF' MASTICATION INVENTOR ATTORNEY April 8, 1958 J. H. sHAcKELFoRD 2,829,639

METHOD FOR- THE CORRECTION OF MALFUNCTIONING MUSCLES OF MASTICATION Filed Nov. 50, 1953 2 Sheets-Sheet 2 40a INVENTOR z f//A/ro/v s//A C/ffz FORD,

' TEF-1D FY@ .ATTORNEY United States Patent O METHOD FOR THE CORRECTION OF MALFUNC- TIONING MUSCLES OF MASTICATION .lohn Hinton Sllackelford, Baltimore, Md.

Application November 30, 1953, Serial No. 394,955

2 Claims. (Cl. 12868) The present invention relates to a method and articulator for the correction of malfunctioning muscles of mastication and it consists in the combinations, constructions and arrangements of parts together with the method herein described and claimed. t

Generally thepresent invention relates to a method and a device utilized to carry out `such method for the treatment of malposition of the mandible due to the loss of posterior teeth in cases in which a few natural teeth remain. The method is based upon a series of clinical observations made by the inventor with relation to the functional behavior of the muscles of mastication, which observations have led the inventor herein to the conclusion that muscle length in the human body is predetermined by the genes and influenced by diet and exercise and that, therefore, there is an optimal distance over which a muscle will function with maximum eiliciency. If'a muscle is forced to function continually over a dis tance greatly in excess of optimal distance, a gradually mounting tension in the muscle tibres will result and, if a muscle is caused to function continually over a distance considerably less than optimal, a gradually mounting tension in the muscle fibres will likewise result. lf a muscle is functioning over a distance less than was established as optimal by the genetic determinations, it would have to bunch and tense itself before it could contract suflciently to reach its work load. Therefore, if such a muscle were stretched toward a distance slightly less than or approximating that over which it functioned before the loss of natural posterior teeth there should be a lessening of tension, an improvement in muscle coordination, a reduction of traumatic mastication and an improved sense of well-being in the patient. Therefore, one of the objects of the present invention is the treatment of patients whose mandibular position has shifted with prosthetic appliances which have caused the muscles to stretch and the angles of the mandible to be displaced downwardly, thereby withdrawing the condyle heads from their traumatic position in the glenoid fossae. When the muscles begin to stretch, the mandible rotates with the angles as the central area in the rotation. Thus, as the condyle heads are withdrawn from their malposition in the glenoid fossae, the symphosis of the mandible and the anterior teeth rotate upwardly slightly distal to the upper anterior teeth. As adjustments of prosthetic appliances are made to permit lateral excursive motions, the mandible can he permitted to move slightly forwardly until a desirable relationship is attained between the upper and lower anterior teeth provided there has not been too great anterior displacement of the upper teeth. This method of `repositioning the mandible in cases where a few natural teeth remain is made possible by the fact that the muscles improve in their functional eciency and coordination when stretched toward their optimal functioning distance, tension in the muscles decreasing, and their rate of fatigue is extended over a longer interval. The inventor has noted that patients treated by the pres- 2,829,639 Patented Apr. 8, 1958 ice ent method have an interval of discomfort of approxi? mately three to live days during the initial stretching of the muscles; that, in the average case, the mandible movement is satisfactorily completed in from six weeks to two months; and that an improvement in the coordination of the adjacent `sets of muscles such as the facial muscles, the muscles of the floor of the mouth, the tongue, and those involved in positioning and moving the head is noted by the end of the third month.

It is accordingly an object of the invention to provide a method of correcting the malfunctioning of the muscles of mastication.

Another object of the 'invention is to provide a novel articulator for accomplishing the first-mentioned object.

Other and further objects of the invention will become apparent from a reading of the following specification taken in conjunction with the drawings, in which:

Figure l is a side elevational view of an articulator forming a part of the invention,

Figure 2 is a top plan view thereof,

Figure 3 is a bottom plan view thereof,

Figure 4 is a vertical sectional view of the device illustrated in Figures l to 3, inclusive,

Figure 5 is a sectional view taken substantially along line 5--5 of Figure l, Y

Figure 6 is an end elevational view taken in the direc` shown therein, in Figures 1` to 6, inclusive, an articulatorj comprising a horizontally extending substantially rectangular base plate 10 having a reduced rectangular portion 11 at the inner end thereof from which there extends centrally and upwardly a pin 12. There is also provided a vertically extending substantially square hollow housing generally indicated at 13 having an inner wall 14, an outer wall 15 and a` pair of side walls 16. A vertically extending block 17 is snugly and slidably mounted in the housing 13 and isprovided in its lower end with a socket 18 for snugly and slidably receiving therein the:

upper end of the pin 12.`

The outer wall 15 is provided with thickened portionsA 19, 20 and 21 in` which thereis-threadably mounted set screws 22, 23 and 24,.respectively. The screw 22 is adapted to bear against the side of the pin 12 while the screws 23 and 24 are adapted to bear against the adjacent side of the block 17. Centrally axed in the upper end of the block 17 and extending upwardly therefrom is a pin 25 which is exteriorly threaded for the reception thereon of a nut 26.

A horizontally extending substantially rectangular upper plate 27 of relatively narrower width than the plate 10 is provided with a substantially square reduced portion 28 at its inner end and the upper end of the block 17 is provided with a susbtantially square socket 29 for the reception therein of the reduced portion 28. An upwardly extending transverse shouldcr 30 is provided upon the plate 10 and is adapted to abut against the outer face of the lower portion of the wall 15. The underside of the plate 27 is provided with a transversely extending shoulder 31 which is adapted to abut against the upper edge of the wall 15 and it will be seen that the lower edge of the wall 1S is cut away sufficiently to permit the horizontal passage ltherethrough of-,thefgteduced portion 11 of the plate 10.

Referring now to Figure 7. it will be seen that there is therein shown a crude representation of portions of the human skull in YAwhichA 32 designates fthe :auditory c anal, and -in `which the interarticular brocarti'lage for :meniscus is shown at .33. Bearing vagainst the meniscus 3,3 yis the mandibular condyle 34 of :the inferiormaxillary `35 the superiorrmaxillarfy being -illustr-,ated fat 36. A37 indicates the posterior border of the fossa while .38 indicates the articular eminence. The upper teeth are generally lindicatedat 39 while the .lower `teethare ,generally indicated at 40. Y

.In Figures '8 `to 1-0, inclusive, the upper teeth 3.9, the lower teeth -40 together with ,the lowerjaw and mandibular condyle are graphically illustrated t0 progressively show the functioning-of the present method, the-corrected llowerteeth beingindicated-at-Mlazin `Figures Y9 and l0 while .the lower .'teeth, prior to `ntlleir Lcorrection vby 'this method, .are indicated at 40 :in .Eigure ;8. :In all Ythree figures, 8 to 10, inclusive, ther ristindicated at X the pivotal point of the lflower jaw prior to zits correction and at X the desired pivotal pointfor Jsuch :lower tjaw in order to bring Aabout'the 'fobjects of the present invention.

-In carrying -out the present invention plastercasts of conventional character are vatlixed ,to the upper side of the plate 10 and lower side of the ',plate 27 lfin the -identical relationship to each other that they have in their position yina patients mouth. The articulator is v.preferably formed of aluminum or other 'light metal I,to ,make it suiciently `light in weight :to 'avoidv the straining of the hands Vof v:tecltinicians working with vthe gsame and it will be apparent tthat the plates 10, and 27 so designed that lateral motion with respect to each other ;is impossible due to Ithe close iittin'gof ,the reduced portions 11 and 28 with their lthree associated ,elements. When the casts .have been .mounted upon :the plates 10 and 27 the bite of such casts may be @cnedra-predetermined distance by lfirst loosening the screws 2.2, .23 and 2.4 to therebygpermit vertical movement :ofpthe block 17. The inner -face of the block 17 indicated iat 42, is :preferably provided lwith 'millimeter calibrations so that the distancejthe .casts (are moved apart may be treadily determined afterwhich'thesscrews 22, 23jaud 24-aregagain tightened .to `maintain such distance. It mll `:be apparent that the bite, although opened, :will :remain :always in horizontal relation;

The amount `of .the .openinghetween the :two casts aforementioned will :be-detetminedby previous -observations .ofthe patient -to determine the ,distance it1is desired to move the pivotal point ofrthgmandible Acondile 34, `that is Ato say -the distance .between .and X7. The partial dentures and, in ysome ca sesga partial lower and lfull upper denture are then buil-t up bythe operator to open the bite relationship between the two casts while maintaining their horizontal relationship with one another. This is illustrated graphically at 40a in Figures 9 and l0 which are, of course, greatly exaggerated in order to illustrate the principle employed herein. When the dentures have been so built up, it will be apparent that initially the rearwardends of the upper tooth assembly will meet with the rearward ends of the lower tooth assembly as indicated in Figure 9 thus forcing the muscles such as, for example, the masseter muscles, to distend a greater distance to allow vfull closure of such teeth as indicated in Figure l0. This action will bring .the pivotal point of the mandibular condile 34 from that indicated at X to the corrected position indicated `at X', thus lessening the tension in such muscles and eventually adding to the general well being of the patient and, in many cases, preventing loss of hearing due to the occlusion of the vauditory canal 32 by upward and rearward pressure of the mandibular condi-le 34 against the auditory meatus of. the canal 32.

While but one form of the .invention vhas been lshown and described herein, it will be readily appa-rent -to those skilled in the art thatlmanyminor modications may be made Without departing 'from the spririt of the invention or the scope of the appended claims.

What :is claimed is:

1. The method `of correction of malposition of the mandible due to loss of certain posterior teeth of a person having dentures for Ysaid -lostteeth comprising first, fabricating plaster vcasts ofthe lupper and lower teeth and dentures of the person .needing such correction; next, moving said casts apart to ,a predetermined spaced parallel relation with respect to each other; and, tinally, building up said dentures toopen the bite relationship between said casts kwhile .maintaining their Aparallel relationship to each other.

2. The method of correction of malposition )of the mandible due to loss of posterior teeth-of .a-.person having dentures for said lost teeth comprising rst, determining the distance between the position ofthe lcondiles of the malposed mandible and their proper positions; and next, building up said dentures an amount necessary to provide fulcruming contact points whereby-saidfcondile heads are forced to Imove to correct kpositions :whe'nthe :upper and lower teeth and dentures are broughttogether.

References Cited in the tile of fthis patent UNITED STATES PATENTS 

